OCKLOCKNEE AND AUCILLA RIVERS. 
97 
EOCENE. 
Although not exposed at the surface, the Eocene doposits are 
reached by deep wells. This has been shown by the samples from 
the well of the Bonheur Development Company. This well, which 
is located in Wakulla County, 16 miles south of Tallahassee, has 
reached, at the time, of publication of this report, a depth of 2000 
feet. The. well, which is the deepest in West Florida, is of much 
interest, as it shows the presence of a great thickness of calcareous 
formations underlying this part of the State, The samples of drill¬ 
ings from the well have been collected and preserved by Mr. B. M. 
Cates, who also presented a set of the drillings to the State Geolog¬ 
ical Survey. With the. exception of the Oligocene limestones near 
the surface, this well passes through Eocene deposits, chiefly lime¬ 
stones, and apparently is still in Eocene deposits at the depth of 
2,000 feet. The well is being drilled as a test well for oil. 
OLIGOCENE. 
CHATTAHOOCHEE FORMATION. 
The type locality of the Chattahoochee formation is at the Chat¬ 
tahoochee Landing on the Apalachicola River in Gadsden County. 
The thickness of the rock exposed in the cut for the public road at 
this landing is as much as 65 feet, and the full thickness of the 
formation is evidently considerably greater. The. rock of this for¬ 
mation as exposed at this place consists of rather impure limestone, 
the impurity being chiefly clay. The deposits are stratified, ledges 
of rock of medium hardness alternating with softer, more clayey or 
marly layers. The inclusion of clay in the rock is about in the 
proper proportion to form a natural cement, the rock nearby at 
River Junction having been used in a limited way for that purpose. 
The limestones of the Chattahoochee formation found in Leon, 
Jefferson and Wakulla counties, although representing an eastward 
extension of this formation, are for the most part harder and more 
nearly pure than are. those at Chattahoochee Landing. In Wakulla 
County this rock has been used as a material for concrete and for 
road building purposes. The following analysis of a sample of this 
rock from the Griscom plantation near Lake Iamonia has been made 
by the State Chemist. The sample is from a well and was taken at 
a depth of 60 feet from the surface. 
